The present invention relates to a centrifugal casting unit for the production of precision castings.
The centrifugal casting technique enables precision-cast components, which represent pure bodies of revolution, to be produced without an excessive loss of material as the result of sprues and risers, and the like.
In contrast to these bodies of revolution, the sprues, etc., constitute an important source of casting material losses in the case of irregularly shaped precision-cast components, such as, for example, turbine blades, which cannot be produced as centrifugal castings. The "recycling of cast material" is accordingly very high in the production of precision-cast components of this type. The material utilization could be increased by reducing this recycling, and the manufacture of components of this type could be rendered more economical.
A centrifugal casting unit according to the present invention achieves this requirement for reduced recycling of cast material by a practical arrangement. In addition, high-quality precision castings having a homogeneous and dense structure are obtained by the use of vacuum in conjunction with the centrifugal effect.
In addition to the turbine blades mentioned, further workpieces, for the production of which the subject of the invention is particularly suitable, are, inter alia, turbine-discs with shape-elements running in the radial direction, as well as other types of rotating components. These rotating components possess very thin-walled shape-elements, which suffer high thermal and mechanical stresses during operation. Accordingly, these components must be produced with a dense, pore-free structure. In components of this type, particular importance attaches to the blade walls, which run essentially radially, and to guideribs, which have to be made as thin as possible in the interests of minimizing the resistance to through-flow during use. Economical production of components of this type, accompanied by technically faultless material-related conditions in such components is required. These requirements provide the impulse for developing the present centrifugal casting unit.